In 1986, the Cokeville Elementary School crisis occurred when David and Doris Young took 167 hostages — 150 children and 17 adults, one being an unlucky UPS driver — at the school by bringing in a bomb which the couple attached to themselves with a lanyard.
David Young had been the town marshal but had been fired for his odd, erratic behavior. Doris Young had been a café worker in the town he had met while living there. He claimed to be acting as a revolutionary, but part of his demands included $300 million dollars.
Doris accidentally detonated the bomb while her deluded husband was using a restroom. He returned and murdered her, and then killed himself after wounding a teacher. All of the hostages survived, many leaving the classroom through the windows after the blast.
The incident is extremely unusual in that it was associated with a very large number of reports of the presence of angels seconds prior to the blast, who, according to those present, directed everyone to the far side of the room near the windows.
(Thanks to the Wyoming State Historical Society.)